Communications & Media

Mystery still surrounds origin of iconic button grass plains

Fifty years on, mystery still surrounds the origin of the iconic button grass plains of south west Tasmania.

Situated across western Tasmania and occupying much of the World Heritage Area, ecologists and scientists have been divided for half a century over whether these landscapes naturally evolve or are created by fire management practices.

“In 1968, Tasmanian Professor of Botany WD Jackson published a really fascinating paper about western Tasmania and the role fire had in shaping its landscapes,” Professor David Bowman, University of Tasmania’s School of Natural Sciences, said.

“He anticipated a lot of ideas in modern fire ecology and he formulated the theory that the landscapes existed were finely balanced between treeless or forested, and that was all entangled with fire regimes used by the indigenous people.

“In 1968, these were amazing ideas, that plants could influence fire activity and that fire activity could shape landscapes, that landscapes could be shaped by cultural practices.”

2018 marks the 50th anniversary of Jackson’s theory, which went on to influence global thinking about fire and landscapes.

“He was really the first botanist who floated the idea that landscapes could exist in alternative states depending on fire,” Professor Bowman said.

“Previous beliefs centred on vegetation was predictably determined by climate and soils, and that fire was unable to substantially affect vegetation patterns.”

As part of his lifelong work, Professor Bowman’s recent research into Jackson’s theory aims to further inform the ongoing debate.

“Truth is, it is both, it depends which part of the landscape you look at.

“There are some excellent examples of trees invading the margins of treeless plains, but there is also clear evidence that vegetation patterns have been remarkably stable of 100s, and is some cases 1000s, of years reflecting underlying geological controls.

“There needs a lot more research to better understand the role fire plays in creating and maintaining these unique, iconic Tasmanian landscapes.

“The outcome will not only help towards wildlife and fire management, but the legacy of Tasmanian Aboriginal people and their practices towards fire management, or patch burning.”